Question

A plane monochromatic light wave with intensity I0 falls normally on the surfaces of the opaque screens shown in Fig. 5.20. Find the intensity of light I at a point P

(a) located behind the corner points of screens 1-3 and behind the edge of half-plane 4;

(b) for which the rounded-*** edge of screens 5-8 coincides with the boundary of the first Fresnel zone.

Derive the general formula describing the results obtained for screens 1-4; the same, for screens 5-8.

Answer 1

When the screen is fully transparent, the. amplitude of vibrations is 1/2 A1 (with intensity

A1 being the contribution of the first Fresnel zone.

In 5 to 8 the first term in the expression for the amplitude is the contribution of the plane part and the second term gives the expression for the Fresnel zone part. In general in (5) to